It was unclear if Trump was referencing Deputy Attorney General Rod Rosenstein or Special Counsel Robert Mueller.

On Wednesday, the Washington Post reported that Mueller was investigating if Trump obstructed justice when he fired Comey. A spokesman for Trump's personal attorney had strong words in response to the news.

"“The FBI leak of information regarding the president is outrageous, inexcusable and illegal,” Mark Carallo told the Washington Post.

The Washington Post reported Thursday that Jared Kushner's business dealings were also being scrutinized by Mueller's team.

Trump's Friday morning tweet capped off 24 hours of comments on Twitter about the investigation, including several remarks about his opponent in the 2016 election.

Why is that Hillary Clintons family and Dems dealings with Russia are not looked at, but my non-dealings are?